London Ohio Weather Forecast Discussion

529
FXUS61 KILN 080632
AFDILN
Area Forecast Discussion
National Weather Service Wilmington OH
232 AM EDT Wed Oct 8 2025
.SYNOPSIS...
A cold front will move south through the Ohio Valley early this
morning with high pressure of Canadian origin building into the
Great Lakes today. Dry and cooler conditions will arrive behind the
front and continue through the end of the week, as the large area of
high pressure builds across the Great Lakes.
&&
.NEAR TERM /THROUGH TODAY/...
Mean longwave H5 trof shifts east of the area this morning with
northwest flow aloft developing. Expansive surface high pressure of
Canadian origin to build into the Great Lakes today. Lingering post
frontal clouds associated with the exiting system across the
southeast will clear the area early this morning. Cumulus clouds
will develop from the late morning into the afternoon with the best
coverage across central Ohio. Northeasterly winds and CAA will keep
high temperatures on the cool side - ranging from the mid 60s north
to around 70 south.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM THURSDAY/...
Expansive surface high pressure of Canadian origin settles over the
Great Lakes overnight. Skies clear with the loss of heating this
evening and winds decrease to around 5 mph. Temperatures drop to lows
in the upper 30s to lower 40s. Pockets of patchy frost can`t be
ruled in protected areas across the north but this is a limited
chance due to temperatures being marginal and with wind staying up.
High pressure dominates the weather Thursday with only few to
scattered cumulus clouds. High temperatures range from the lower and
mid 60s north to the upper 60s south.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
On Thursday evening, a sprawling area of surface high pressure will
be centered over the state of New York. This high will extend well
to the west and southwest, providing a dry air mass across the Ohio
Valley for the start of the extended forecast period. Radiational
cooling conditions will be near-ideal on Thursday night / Friday
morning, with clear skies and very light easterly winds. Min temps
are expected to range from the upper 30s to around 40, and some
outlying areas might get into the mid 30s, particularly north of
Dayton and Columbus. Frost is expected for the northern third of the
ILN CWA.
On Friday, a compact closed upper low will move southeast into the
Great Lakes, but any precipitation associated with the southern
extent of the trough is expected to dissipate before reaching the
ILN CWA. With a return to southerly flow on Friday, temperatures
will begin a warming trend, with upper 60s for highs on Friday and
lower 70s over the weekend.
Conditions over the Ohio Valley will likely remain tranquil over the
weekend, though the overall weather pattern will be somewhat
complicated -- as the low over the Great Lakes and another low off
the coast of the Carolinas are forecast to merge together somewhere
off the mid-Atlantic coast. The ILN CWA is expected to be on the
western periphery of this complicated array of weather systems, with
little to no impact expected. Gradually warming temperatures are
expected going into next week, but with very low confidence on
getting any additional rainfall into the area.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
Mean longwave H5 trof shifts east of the area this morning with
northwest flow aloft developing. Expansive surface high pressure of
Canadian origin to build into the Great Lakes today. Lingering post
frontal clouds associated with the exiting system generally in the
MVFR category will improve to VFR from northwest to southeast prior
to sunrise.
VFR cumulus clouds will develop from the late morning into the
afternoon with the best coverage across central Ohio. These clouds
clear this evening with the loss of heating.
Northerly winds at 10-12 kts become more northeasterly thru the day
and then decrease to between 5-7 kts overnight.
OUTLOOK...No significant weather expected.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.
&&
$$
SYNOPSIS...AR
NEAR TERM...AR
SHORT TERM...AR
LONG TERM...Hatzos
AVIATION...AR

NWS ILN Office Area Forecast Discussion